The development of macular degeneration, one of the leading causes of blindness on the planet, is "significantly" influenced by people"s diet, according to a recent study.
Research carried out by experts at Tufts Medical Center shows that eating a diet high in vitamin D, as well as the nutrients betaine and methionine, might help reduce the risk of macular degeneration.
For the study, entitled "Smoking, Dietary Betaine, Methionine and Vitamin D in Monozygotic Twins with Discordant Macular Degeneration: Epigenetic Implications", scientists analysed the records of identical twins from the US World War II Twin Registry.
They found that smoking is also a major risk factor for macular degeneration in people with equal genetic susceptibility to the disease.
The research, which is published in the journal Ophthalmology, is the first to look at identical twin in which one twin had early age-related macular degeneration (AMD) and the other had late-stage AMD.
Lead researcher Dr Johanna Seddon, director of the Epidemiology and Genetics Service at Tufts Medical Center, said AMD is "highly heritable", with genetic factors determining up to 71 per cent of the disease"s severity.
Through examining identical twins with the same genes but whose disease was at different stages, researchers were able to identify environmental and behavioural factors that could contribute to the severity of the disease, she said
"We wanted to know why, if they have the same genes, do they have different stages of the disease?"
She advised: "Eat a healthy diet with lots of fruits and vegetables, and that can make a difference - even if you have a genetic susceptibility to macular degeneration and, of course, don"t smoke."
It is hoped the study will help to raise awareness of the risk factors for AMD, which can help to reduce the number of people suffering form the disease worldwide.
According to the AMD Alliance, AMD largely occurs in people over the age of 55, though can affect younger people with a genetic predisposition to the condition.
by Alexa Kaczka